JPH0250238B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to the control of refiners, and more particularly to the calculation of main drive motor speed based on real-time process measurements and adjustable constants with respect to the horsepower produced by the main drive motor of a refiner. The present invention relates to an adaptive refiner control that operates to provide a value. PRIOR TECHNOLOGY The basic problem facing paper mills today with respect to refining is that the refining strength, determined by the shape of the refining plate and the power applied to the paper stock, cannot be maintained at a given grade even as production volumes vary. By keeping constant for paper and using the same refining equipment to make different grades of paper with different production volumes and with newly set horsepower/day/ton values and refining strength values. be. Current technology has a constant speed main drive motor, so to vary production output,
The refining power can be adjusted to obtain the required horsepower/day/ton, but since the motor speed cannot be changed, the refining strength cannot be changed in fact. Under the above circumstances, paper mill personnel must continue to adjust the refiner power to find the optimal refiner operating condition settings that yield the desired results. Such a setup often results in wasted power. SUMMARY OF THE INVENTION It is an object of the present invention to provide control of the refining intensity that is adapted to the specific conditions and processes of the refiner. The above objects are achieved by using a variable speed drive as the main drive motor and providing adaptive refining intensity constant control that solves the following problems. The problems are: 1. Determine the speed at which the main drive motor should rotate with respect to the net horsepower applied to the refiner; 2. Determine the no-load horsepower in real time and use that data to optimize the energy conditions of the entire refiner. 3. Determine the actual net horsepower given to the refiner; 4. Determine the required speed of the adjustment mechanism that is inversely proportional to the power level of the main drive motor, and the speed range that can be stably controlled. can be adjusted freely. Specifically, the objective is to solve the above problem through the solution of several unique algorithms that derive a calculated main drive motor speed that is related to the net horsepower produced by the main drive motor from real-time process measurements and adjustable constants. Achieved by solving. Therefore, the accuracy of control is determined by the accuracy of no-load horsepower. Therefore, no-load horsepower is determined using a unique linear equation. A two-dimensional array representing the initial values of the process in real time is defined. This initial value is a value that takes into consideration other mechanical and fluid losses in addition to the no-load horsepower when the speed is changed with the normal production amount constant. Accuracy hereby is further improved by completely solving the no-load horsepower equation using real-time measurements of flow and concentration. Here, the actual net horsepower can be calculated using the no-load horsepower calculation and the actual horsepower measurement from the main drive motor. The results of the series of calculations described above are used as feedback to indicate the imbalance between the set horsepower/day/ton and the actual horsepower/day/ton. Equilibrium conditions are achieved by adjusting the spacing of the refining plates. At the same time the net horsepower is adjusted, the required speed equations are processed. This required speed is a function of the contact edge length per revolution of the refining plate blades, the shape of each refining plate, the actual net horsepower calculated earlier, and the fiber It is constant with respect to the strength factor, which is a numerical constant representing the desired physical property. A variable speed regulator is used to ensure that the final control element, ie the calculated result, is accurately met by the refiner gear motor.
The gear motor actual speed is an inverse function of the power drawn by the main drive motor, and as the applied power increases, an adjustable constant causes the rotational speed of the regulator to decrease. Due to this unique feature,
A common source of control instability that occurs when the drive motor is operated near its full load horsepower rating is eliminated, and the refining plate is adjusted to a constant, predetermined speed. SUMMARY DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally speaking, the present invention provides a method for maintaining constant refining intensity for a stock slurry passing through a disk cliff reiner as production rates and adaptive power conditions change. It is something. This is accomplished using several unique control algorithms and control strategies that combine to relate the rotational speed of the refining plate to the power drawn by the main drive motor. Intensity is defined as the given refining net horsepower divided by the length of contact when the refining plate blade edges cross each other per unit time (IC/REV). Refining net horsepower is defined as the total main drive motor horsepower minus the no-load horsepower. No-load horsepower is determined by the fluid friction forces exerted by the stock slurry (fiber suspension) between the refining plates, gland friction, bearing friction, internal turbulence, and other minor factors that cannot be clearly defined. Against the resistance of
This is the total horsepower required to rotate the refining plate. The present invention determines set points for process operating conditions, calculates the required refiner horsepower,
Adjust the refining plate distance at a speed commensurate with the given horsepower, determine the actual net horsepower using the unique initial value input method for no-load horsepower definition described above, and run the process. It provides a technique for calculating the rotational speed of the main drive so that the refining intensity remains constant even under changing conditions. With reference to FIG. 1, the elements of adaptive refining strength constant control will be explained individually. Mode Selection Elements The mode selection elements, generally indicated at 10, are operator-selectable control methods (i.e., freeness control, couch vacuum control, horsepower/
(e.g. day/ton control) provides a means to indicate the mode of operation in which the control system will function.
A menu-based format is used, and once a mode of operation is selected, the appropriate scaling and range number of the oscillator is assigned to the system set point by an associated software subroutine. Process Set Point Element Process set point element 12 represents a means for setting the desired level of refining intensity. When the Horsepower Day/Ton (HPDT) operating mode is selected, the Proportional Integral Derivative (PID) function is unnecessary and is bypassed, so that the desired HPDT set point is accepted directly into the Programmable Fine Controller (PRC) element 14. It will be done. Programmable Refiner Controller Element (PRC) The programmable refiner controller element 14 includes:
As its input it receives the output of a process set point element 12 representing the desired HPDT set point. Depending on the selected operating mode, the feedback signal is either the calculated percent net horsepower/day/ton or the actual net horsepower, as described below under the "Mode Selection" subheading. Programmable refiner controller element 14 includes:
Depending on how much the feedback signal deviates from the set point signal, it initiates the corrective action required by the refining plate positioner, i.e. it changes the relative position of the refining plate until an equilibrium condition is achieved. Increase or decrease. The rate of change of speed at which repositioning of the refining plate takes place is determined by gear motor speed calculation element 16. Gear Motor Speed Calculation Element The gear motor speed calculation element 16 receives the actual net horsepower signal from the actual net horsepower element 18, and determines the speed at which the plate-to-plate adjustment gear motor rotates through processing of a unique linear equation. The gear motor speed calculation formula changes the speed of the gear motor in an inverse relationship so that as the horsepower of the main drive motor increases, the rotation speed of the gear motor adjustment mechanism decreases. This actual method is described in Japanese Patent Application Laid-Open No. 108788/1983. Refining Plate Adjustment Element Refining plate adjustment is performed using a refining plate adjustment element 21 in combination with a standard motor starter and reversing contactor. The direction of rotation and the duration of the ON time are determined by the required refiner horsepower factor 20, and the speed of the gear motor is predetermined and self-adjusting through the gear motor speed calculation factor 16. No-Load Horsepower Element The no-load horsepower element 22 represents a method for determining an accurate no-load value. The no-load value is a variable whose value changes with the load factor of the main drive motor under most conditions. The term "no-load horsepower" is defined in the subheading "Overview." To accurately determine net horsepower, this no-load value must be accurate over the entire load range of the main drive motor. Determination of the no-load value is done by a technique called the initial value input method, in which all the no-load values of the main drive motor at each incremental speed value are arranged in an array. The matrix will represent the true no-load horsepower of the machine under control and will take into account all of the various defined and undefined losses present on the particular machine. The matrix contains two columns recording the instantaneous speed and the corresponding no-load horsepower value at that time. This information, combined with a measurement signal related to the measured speed of the variable speed drive system and proportional to feed concentration and feed flow rate, provides a no-load horsepower value. The use of actual feedstock concentrations and feedflow rates is required to represent changes in concentration or flow rate effects with respect to actual no-load horsepower. The entire process of determining no-load horsepower NLHP is expressed by the following relational expression. NLHP=A+{(CA-CT)/K _C +(FA-FT)/K _F /2} K _C is the variable horsepower constant that adjusts the change in concentration effect on no-load horsepower, CA is the actual concentration, and CT is the setting concentration or target concentration, K _F is an adjustable constant that adjusts the change in flow effect with respect to no-load horsepower, FA is the actual flow rate, FT is the set flow rate or target flow rate, and A is selected by the value of the measured variable RPM. The matrix value horsepower, RPM, is the measured speed variable.

[Table] Actual Net Horsepower Element The actual net horsepower consumed by the main drive motor is defined by the following equation. Actual net horsepower = Actual power / 0.746 - No-load horsepower The calculated actual net horsepower is the actual net horsepower factor 18
is used as feedback information from to gear motor speed calculation element 16, strength calculation element 30, PRC element 14, and percent net horsepower element 24. Percent Net Horsepower Factor The percent net horsepower factor 24 defines the percentage of net horsepower consumed by the main drive motor. This value is derived from the following relational expression. Percent net horsepower = 100 x (actual net horsepower/K ₃ ) Actual net horsepower is derived from the above relational expression and is a constant.
K ₃ is an adjustable constant representing the effective net horsepower. Percent Flow Element The percent flow element 26 determines the actual flow rate at a certain moment and converts this value into a percentage of the maximum flow rate. This value is derived from the following relational expression. Percent Flow = 100 x Actual Flow/K _4Actual flow values are obtained by the use of standard flow measurement devices such as magnetic flow transmitters. In the above equation, K ₄ is an adjustable constant representing the calibration range of the flow measuring device. Percent Net Horsepower Days/Ton Element The Percent Net Horsepower Days/Ton Element 28 is the actual net horsepower delivered by the main drive motor based on the flow rate (T/D) and concentration of the feedstock being processed at a given moment. Calculate horsepower/day/ton. Percent Net Horsepower Day/Ton (%NHDT) is derived from the following relationship: %NHDT = (Percent Net Horsepower/C・P ₁ + P ₂ ) × (Percent Flow Rate × 0.06) where C is the measured concentration value, P ₁ is (1 – P ₂ )/50, P ₂ is the minimum concentration/average concentration, and percent The flow rate is the calculated percentage flow rate, 0.06 is 1/16.62. The use of the above formula to include percent net horsepower-day/ton is not specifically claimed as the invention. This procedure was filed on April 19, 1982,
U.S. Patent Application No. 370577, granted August 28, 1984.
Defined in No. Main Drive Speed Calculation Element The result of the calculation by the main drive speed calculation element 30 is a signal representing the rotational speed of the main drive motor. The required rotational speed of the main drive motor is determined by the following equation. RPM (speed) = Actual net horsepower/IC/REV x Strength coefficient Where, actual net horsepower is the calculated value of actual net horsepower, IC/REV is an adjustable constant representing the refining strength due to the refining plate shape,
The strength coefficient is expressed as: Strength coefficient = Actual net horsepower/IC/REV x RPM. This strength factor is an adjustable constant that represents the required value after the material has passed through the disc refining ironer and refining plate. Proportional-Integral-Derivative (PID) Functional Elements No claims are made herein to standard PID functions that have been well known to those skilled in the art for many years, except in combination with other elements of the present invention. These standard features are used within the inventive concept to improve overall operation. These are included in their respective definitions to make the invention easier to understand and are represented by proportional integral derivative (PID) functional elements 32. Proportionality is the ratio of the change in output to the change in input due to a comparative control action. Integration is a control action in which the rate of change of output is proportional to input. The differential is the ratio of the maximum gain obtained from the proportional plus differential control action to the gain due to the proportional action alone. The three control functions described above can be finitely adjusted with certain limitations and represent a process means for adjusting the motion control system. A similar element 34 is provided to control the main drive speed set point from the drive speed calculation in strength calculation element 30. Hardware Control Circuits Although the individual control circuits or elements described above may be provided by several different circuits, it has been decided that the calculations will be quickly processed by a computer, such as a DEC Mod PDP 11-23E computer. . This PDP 11-23E system includes a 1MB disk drive, an A/D (analog-digital) input card, a D/A (digital-to-analog) output card, and an RSX operating system.
It includes a Pascal (UCDS) version of the compiler. Main Motor Drive Package The main motor variable frequency drive package selected as the variable speed drive control element 47 is
It is a 600 horsepower variable frequency controller supplied by Reliance Electric. Gear Motor Drive Package The gear motor variable frequency drive package selected for the Refineer Gear Motor 52 is:
A 5 horsepower variable frequency controller, Model AS270-OTB, was supplied by Emerson Electric. Gear motor adjustment panel The gear motor adjustment panel is manufactured by Beloit (drawing number D42-400788). Programmable Refiner Controller (PRC) The programmable refiner controller is manufactured by Beloit (drawing number D42−).
400983−G1). Power signal transmitter 36 The selected power signal transmitter 36 is a Scientific
It is Mod XL manufactured by Columbus. Concentration transmitter 38 The concentration transmitter 38 is Mod 710BC manufactured by Dezuric.
It is. Flow Transmitter 40 The flow transmitter 40 is a Mod 2800 manufactured by Foxboro. Freeness Transmitter 42 The selected freeness transmitter is a Mod MarK manufactured by Bolton Emerson. Couch Vacuum Transmitter 44 The selected Couch vacuum transmitter 44, which senses the vacuum in the Couch roll 46, is manufactured by Foxboro. Judgment elements 52, 54 and 56 are of course
Part of the PDP11-23E system. Other operating elements are of course the main drive motor 4.
8, and a refiner 50 including a refiner gear motor 52. Mode of Operation As mentioned above, the PDP11-23E computer was selected to improve the adaptive refiner constant strength control technique. Also, as mentioned above,
PDP11-23E is not an exclusive means of implementation. The control techniques described in detail can be implemented using analog or digital techniques with appropriately selected hardware by those skilled in the art using the device. The operations described below are based on a digital implementation and will be described in subblocks. Finally, all the various motion blocks will be combined together to represent the complete motion technique. Therefore,
FIG. 1 will represent both the hardware of the system and a flowchart detailing the mode of operation of the system. Mode Selection, Set Points, and Decisions The mode selection portion of this control system is performed using a CRT terminal interconnected to a computer. This terminal is an operating mode selection element designated 10. The software module is constructed using an operator-attended keyboard (also element 10).
The mode in which this control system operates is defined by an interaction routine that requires input from the control system (some of the systems), i.e., HPDT mode, Couch vacuum value mode, freeness control mode, etc. The selection mode, set point and decision section control techniques are illustrated in FIG. 1 by elements 10, 12 and 52. Using the interaction data received during initial control preparation, subsequent menus and interactions appear during which appropriate subroutines are selected to define the correct scaling data and constants required for the selected mode of operation. At the same time, various decisions are made based on the same input data. Grade 1 2 3 4 Which one should you choose on the grade input menu paper ? Control mode selection 1 Which refiner to select? 2 Want to run in HPDT mode Y/N? 3 Want to run in freeness mode Y/N? 4 Want to run in couch vacuum value mode Y/N? 5 Want to run in another mode Y/N? The selected mode is is. Lihuaina number is No. is. Is your choice correct, Y/N? Dialogue start 1 The selected grade is is. Is your choice correct, Y/N? 2 Do you want to start automatic control? Y/N? 3 Y = "Automatic control start" subroutine A 4 N = No-load horsepower and actual net horsepower to move to constant readjustment subroutine "B" No-load horsepower element 22 and actual net horsepower element 18
is the speed established from real-time data acquisition techniques -
No-load horsepower data array and no-load horsepower element 22
and the continuous solution of the no-load horsepower equation described above for the actual net horsepower component 18, and is implemented in conjunction with the decision element 54. Therefore, with reference to these elements and equations, the speed-no-load horsepower data array, hereinafter referred to as initial values, is constructed by calculating the no-load values of the individual motors and refiners included in the full speed range of the variable speed main drive motor 48. Establish no-load characteristic curve. The curve obtained in this way takes into account all the horsepower losses due to the various situations mentioned in the "Summary" section above.
It represents the true no-load value at various speed levels of the drive. The schedule below is a typical pseudo code that complements the initial value input operation. This initial value input operation needs to be performed only once before starting automatic control. The initial value entry process is repeated only if mechanical changes are made, such as increasing the horsepower of the motor or changing the position of the refining plate. Pseudocode 1 Start the main drive motor, accelerate it to maximum speed, and start the material pump. 2. Check if inlet pressure and concentration are within range 3. Reduce drive increments 4. Read drive horsepower and speed P ₍₁₎ S ₍₂₎ at each increment 5. Transfer control to grade input menu when finished. Person skilled in the art As can be seen, the number of data points established in the speed-no-load horsepower data array has a significant impact on the accuracy of the resulting curve. A representative initial value data array is shown below in the discussion of the no-load horsepower component and will be used in the following discussion to illustrate the actual operation of the control process. Algorithms explained in equation form could give a more complete understanding of the concept and therefore not be simplified in all cases. The no-load horsepower element 22 operates as follows. 1 Assign the speed input value to the program variable AIN. 2 Using standard array search techniques, compare the value of variable A to the motor speed value that was in the array during the initialization procedure. 3. Find the closest partner to the value contained in the program variable AIN and assign the corresponding value of horsepower at that point to the program variable AOUT. 4 Solve the no-load horsepower equation and assign the calculated value to the program variable NLHP. The following is a numerical representation of the above procedure. NLHP=AOUT+ {(CA-CT)/K _C + (FA-FT)/K _F /2} Where, CA=actual concentration from concentration transmitter 38, CT=set concentration, FA=from flow rate transmitter 40 actual flow rate, FT = set flow rate, K _C = adjustable constant representing concentration change effect based on modified no-load corresponding to different raw materials being processed, K _F = flow rate change effect corresponding to different raw materials being processed. A tunable constant that represents the array value stored at the indicated location in the array by matching the array speed (RPM) value of the AOUT = AIN variable.

【table】

【table】

[Table] The above calculation results show that the above equation described as being applicable in practice is capable of producing results when concentration and flow rate values are taken as valid inputs to the equation. It also shows the procedure for obtaining accurate no-load horsepower values, which is an important part of the overall control technique. The two constants K _C and K _F are empirical and must be determined from actual test runs. Actual net horsepower The value of actual net horsepower is determined by the following formula. ANHP = (actual power/0.746) - NLEP where, ANHP = actual net horsepower, actual power = actual kilowatt value obtained from the power transmitter 36, 0.746 = derived from the conversion formula used when converting KW to horsepower Conversion factors: 1 horsepower = 33,000 ft-lbs/min 1 hp = 550 ft-lbs/sec 1 horsepower = 746 watts 1 horsepower = 0.746 kilowatts NLHP = result of solving the NLHP equation above. Using the above formula for actual net horsepower, the calculation results from the no-load horsepower calculation formula when the motor power is 1000 horsepower are shown below.

[Table] The above calculation results show that the actual net horsepower converted from kilowatts to horsepower is derived as a smaller value by the calculated value of the no-load horsepower by the above equation. Percent Net Horsepower, Percent Flow, Percent Net Horsepower, Horsepower Days/Tons Percent Net Horsepower, Percent Flow Rate, and Percent Net Horsepower Days/Tons are output from flow transmitter 40 and concentration transmitter 38 during the Horsepower Days/Tons mode. The additional inputs provided by elements 24, 26 and 28 of FIG.
Only used when HPDT mode is selected. The conversion of values into percentages is not unique per se and is not a feature of the invention. Percent Net Horsepower Days/Tons Percent Net Horsepower Days/Tons Element 28 represents the procedure disclosed in U.S. Pat. No. 4,184,204 with standard modifications. The purpose of this element 28 is to convert the incoming process measurement signal into a net horsepower/day/ton value using the method described in U.S. Pat. No. 4,184,204.
A modification of this procedure is the percent conversion of the result values required for operation of the present invention, where the above for percent net horsepower-day/ton using percent net horsepower, percent flow, concentration measurements, and concentration ratios. To solve the equation in the form derived from the description, this element 28 is given a variable percent net horsepower. Percent Net Horsepower Percent Net Horsepower Element 24 is equal to Elements 22 and 1
It provides a direct forward conversion of the value determined by 8 to a percentage value. In the numerical example below for the percent net horsepower formula, the constant K ₃ is adjustable and represents the effective net horsepower.
The effective net horsepower can be the maximum rated horsepower of the main drive motor 48 minus its no-load horsepower; if the motor's horsepower is 1000 horsepower and its no-load horsepower is 180 horsepower, then the constant K ₃ is 820 It becomes horsepower. If the actual net horsepower is 600 horsepower, it will be as follows. Percent Net Horsepower = Actual Net Horsepower/K ₃ Percent Net Horsepower = 100 x (600/820) Percent Net Horsepower = 73.1% Percent Flow Percent flow element 26 combines the flow measurement received from flow transmitter 40 with an adjustable constant K ₄ to generate a value representing percent flow rate. The constant K ₄ represents the calibration range of the flow measuring device. The actual flow rate is the value of the output of the flow measuring device at any particular instant. Assuming that the calibration range of the flow rate measuring device is 1000 GPM and the actual flow rate measurement value is 800 GPM, the results are as follows. Percent Flow = 100 x (800/1000) Percent Flow = 80% Gear Motor Speed, Variable Speed Drive and Gear Motor Plate Adjustment These functions are elements 16, 20 and 2 of Figure 1.
1. These are also
It is also disclosed in No. 61-108788. These techniques are incorporated into the present control process to enhance its overall operation and are individually given below by numerical examples. Gear Motor Speed This control part is based on successive solving of linear equations, and various methods are used to make the required calculations regarding the required gear motor speed. The gist of this method is to change the output speed of the gear motor in an inverse relationship to the magnitude of the power of the refiner main drive motor, and its basic linear equation is as follows. GMSR = GMSMX - [ACMMP/(AVMMP/GMSMX)] + GMSMN where: GMSR = Required gear motor speed GMSMX = Gear motor maximum speed (adjustable constant representing the gear motor's maximum rotational speed output), ACMMP = Actual net speed of the main drive motor Horsepower AVMMP = Main drive motor effective horsepower (adjustable constant that represents the maximum rated horsepower in KW that the Refineer's main drive motor can put out), GMSMN = Geared motor minimum speed (adjustable constant in the variable frequency drive controller) Typical example: Main drive horsepower = 200, maximum effective power = 200 horsepower x 0.746 = 149.2KW, maximum gear motor speed = 900 RPM, minimum gear motor speed = 50 RPM, gear motor speed range = 900-50 = 850 RPM, maximum set speed = 850RPM, no-load horsepower = 70 horsepower x 0.746 = 52.2KW

[Table] The above shows that when the actually measured actual net horsepower of the main drive motor changes, the output speed of the gear motor changes in the opposite direction. Variable Speed Drive Variable speed drive element 20 is a standard variable frequency drive controller. There are several manufacturers of this type of drive controller. There are two measurement conditions for the variable speed drive controller: A. It must be capable of accepting remote control signals from the gear motor speed calculation. B. The variable speed drive controller must be sized to accommodate the output requirements of gear motors of various horsepower ratings. The gear motor variable frequency drive package selected as described above is a 5 horsepower variable frequency controller Model AS270-OTB manufactured by Emerson Electric. Gear Motor Plate Adjustment Refining plate adjustment element 21 represents a group of motor starters and reversing contactors that receive commands from programmable refiner controller element 14 . Adjustment element 2 between the above refining plates
1 is manufactured by Beloit (drawing number D42-400788). Programmable Refiner Controller The microprocessor-based programmable refiner controller element 14 described above is manufactured by Beloit (Drawing No. D42-400983-G1). Briefly, this operation involves receiving an input signal from a remote signal source, comparing this signal with a measured signal from a controller, and taking corrective action on the disk positioner depending on the speed and direction of the rotational signal. Consists of. This is also representative of a controller that can be used to implement the present invention. Main Drive Speed Calculations The main drive speed calculations shown below represent a unique method for determining the required rotational speed of the main drive motor 48 connected to the disc refining iner 50 to vary process conditions to maintain a constant refining intensity. ing. Drive speed calculation ｜←Speed set point PID function←Speed ｜Variable speed main drive motor Refining strength is the contact length when the edges of the blades of the refining plate cross each other per unit time by applying the given refining net horsepower. It is predetermined by the general formula (IC/REV) divided by The required speed is the result of a continuous solution of the following unique equation: RPM (Speed) = Actual Net Horsepower/IC/REV x Strength Factor where Actual Net Horsepower is the mathematical result obtained from the Actual Net Horsepower formula above. IC/REV is 1
is a function of the contact edge per revolution (adding the number of blades on the refining plate at the rotor position multiplied by the number of blades at the stator position multiplied by the length of the blade in each area of the refining plate, (This is multiplied by the number of revolutions per minute.) Referring to FIG. 2, the following applies. IC/M=2 [(B _R1 ×B _S1 ×L ₁ ) + (B _R11 ×B _S11 ×L ₁₁ )
+ (B _RN ×B _SN ×L _N )] × RPM where B _R1 = number of rotor blades in region I, B _S1 = number of stator blades in region, L ₁ = length of region blades. RPM = revolutions per minute.

TABLE The strength factor is in reality an empirically adjusted constant used to describe the desired result from the refining process. This coefficient can be expressed by the following relational expression. Strength Factor = Actual Net Horsepower/IC/REV x RPM Using the same values of horsepower and RPM used earlier, the strength factor used in the following discussion is obtained below. Motor horsepower of main drive motor 48 is 1000
Horsepower, actual net horsepower 819.4hp, speed 900RPM
Then, the strength coefficient IF is IF=819.4/(395936×900) IF=23 ^-5 . As mentioned above, this coefficient represents a combination of three variables: the actual net horsepower, the constant IC/REV representing the refining strength depending on the shape of the refining plate, and the rotational speed, which They are combined to create the desired product. By determining the strength coefficient, the drive speed calculation is as follows. RPM (Speed) = Actual Net Horsepower / IC / REV × Strength Coefficient RPM = 819.4 / (395936 × 23 ^-5 ) RPM = 899.794 The speed calculated now becomes the set point value for the PID functional element 34. The calculated output from PID function 34 is provided to the speed set point section of variable speed drive control element 47. A feedback signal is returned from the variable speed drive control element 47 to the PID function 34 to bring the drive speed to the value determined by the output of the PID function 34. According to FIG. 3, the control shown here combines the physical measurements of the process, the unique algorithms that define the various values, and the control hardware necessary to provide adaptive constant-strength control of a disc-type refining machine. It consists of a combination of clothing. FIG. 3 summarizes the entire detailed description of the invention in simple block (flowchart) form. The function of each block has been described above. As mentioned above, the purpose of the present invention is to provide a control system that is adapted to reality, and to control freeness, horsepower,
The process is to vary the process operating conditions to maintain a constant refining intensity using one of several primary control modes, such as day/ton control, couch vacuum control, etc. As shown in Figure 3, the basic steps are as follows. A. The operator initiates the primary mode of control and establishes the set point values for the selected mode. B. When the process measurements change from the set point, the refining plate adjustment control repositions the refining plate at a rate of speed change determined by the plate adjustment speed calculation. The main drive power changes as the position of the refining plate changes. C Changes in main drive power are recognized by the no-load horsepower calculation and actual net horsepower calculation elements. The new no-load horsepower value is incorporated into the actual net horsepower calculation. The resulting calculation becomes a process measurement signal that is fed back to the programmable refiner controller to balance the control system to the set point value. D The newly calculated actual net horsepower value is also provided to the speed calculation element of the speed calculation algorithm to obtain the new speed set point value. E The main drive motor variable speed controller is instructed to readjust its speed by the output of the speed calculation element and the proportional-integral-derivative function. FIG. 4 schematically shows the overall flow of the basic steps of the control method according to the present invention. According to this diagram, assuming that a variable speed motor is used as the main drive motor of the refiner, first, the stock density and Detects the stock flow rate, detects the speed and power of the main drive motor, calculates the no-load horsepower of the main drive motor in response to the stock density, stock flow rate, and main drive motor speed, and calculates the no-load horsepower of the main drive motor based on the detected power. In response, convert no-load horsepower to actual net horsepower, calculate percent net horsepower-day/ton from the no-load horsepower and actual net horsepower in response to stock flow rate and stock concentration, and calculate percent net horsepower-day/ton from the no-load horsepower and actual net horsepower in response to stock flow rate and stock concentration. /ton, required horsepower・
Calculates the gear motor speed from the day/ton set point, actual net horsepower, main drive motor effective horsepower, and geared motor maximum and minimum speed, and calculates the actual net horsepower, an adjustable constant representing the refining intensity, and an adjustable The speed of the main drive motor is calculated from the strength coefficient determined as a constant and is supplied to the variable speed main drive motor. Significance The significance of the present invention is manifold and provides adaptive control to maintain constant refining intensity in response to changes in output and given power conditions for stock slurries passing through a disc-type refiner. It includes multiple means and methods. These methods and means have the following effects. 1. As a first step, by providing a method and means for accurately determining the no-load horsepower value of the main drive motor, the accuracy of the overall control technique is improved and a uniform product is obtained from the disc-type refiner. 2. Providing a means and method for controlling the intensity of the refining action based on process measurements and necessary calculations would be an advantage contributing to additional benefits and uniform product production. 3. Providing a means and method for adjusting the rotational speed of the main drive motor based on the solution of unique equations aids the ability of control technology to reduce the power consumption of conventional constant speed drive motors. A uniform product is produced. 4. Improving the controllability of the disk refining variables, i.e. the horsepower used to position the relative refining plates, will result in improved products with lower energy consumption in certain circumstances. Although the present invention has been described above in detail with reference to its preferred embodiment, the present invention is not limited to this specific embodiment, and numerous changes and modifications of the present invention may be made without departing from the spirit of the present invention. It will be clear to those skilled in the art that

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an adaptive refiner constant strength control constructed in accordance with the present invention and connected to a refiner to control the refiner based on real-time process measurements; FIG. FIG. 3 is a simplified block diagram of the present invention, and FIG. 4 is a diagram showing a schematic flow of the control method according to the present invention. 10...Mode selection element, 12...Process set point element, 14...Programmable refiner controller element, 16...Gear motor speed calculation element, 1
8...Actual net horsepower element, 20...Required refiner horsepower element, 21...Refining plate adjustment element, 22...No-load horsepower element, 24...Percent net horsepower element, 26...Percent flow rate element , 28...Percent net horsepower/day/ton element, 30...Main drive speed calculation element, 32,3
4... PID functional element, 36... Power signal transmitter,
38...Concentration transmitter, 40...Flow rate transmitter, 42
... Freeness transmitter, 44 ... Couch vacuum value transmitter, 46 ... Couch roll, 47 ... Variable speed drive control element, 48 ... Main drive motor, 5
0...Refiner, 52...Refiner gear motor.

Claims (1)

[Scope of Claims] 1. A method for controlling a papermaking refiner that is equipped with a gear motor that adjusts the distance between refiner plates and is driven by a main drive motor, comprising: (a) controlling the stock concentration and stock flow rate of the refiner; (b) detecting the speed and power of the main drive motor and generating corresponding speed and power signals (36, 40); (47); (c) generating a no-load horsepower signal for the main drive motor in response to the concentration signal, the flow rate signal, and the speed signal; and (d) generating a no-load horsepower signal for the main drive motor in response to the power signal. (e) converting the no-load horsepower and the actual net horsepower into percent net horsepower in response to the flow signal and the concentration signal;
Steps to convert to days/tons (24, 26, 28)
and (f) generating a gear motor speed signal from the percent net horsepower/day/ton, the required horsepower/day/ton set point, the actual net horsepower, the main drive motor effective horsepower, and the maximum and minimum speeds of the gear motor to drive the gear motor. steps (16, 20, 21) for supplying a speed signal to the gear motor; (g) an adjustable constant representing the refining strength determined by the actual net horsepower, the shape of the refining plate, and the desired refining result; A method for controlling a refiner comprising the steps of: generating a drive motor speed signal from a strength coefficient defined as an adjustable constant representing the main drive motor;